This book offers a comprehensive and engaging introduction to the criminal justice system of England and Wales. Starting with an overview of the main theories of the causes of crime, this book explores and discusses the operation of the main criminal justice agencies including the police, probation and prison services and the legal and youth justice systems. The fourth edition has been revised, updated, expanded and features a new expert co-author. This book offers a lively and critical discussion of some of the main themes in criminal justice, from policy-making and crime control, to diversity and discrimination, to the global dimensions of criminal justice, including organised crime and the role performed by transnational policing organisations to combat it. Key updates to this new edition include: increased discussion of the measurement, prevention and detection of crime; a revised chapter on the police which discusses the principle of policing by consent, police methods, power and governance, and the abuse of power; further discussion of pressing contemporary issues in criminal justice, such as privatisation, multi-agency working, community-based criminal justice policy and the impact of the Covid-19 pandemic on the delivery of criminal justice policy; a revised chapter that deals in detail with new and emerging forms of criminality and the response of the UK and global criminal justice system to these developments. This accessible text is essential reading for students taking introductory courses in criminology and criminal justice. A wide range of useful features include review questions, lists of further reading, timelines of key events and a glossary of key terms.